fix(did-you-mean): suppress suggestions for valid queries and matching terms

includes/classes/Feature/DidYouMean/DidYouMean.php

@@ -127,11 +127,22 @@ public function get_suggestion( $query = null ) {
 			return false;
 		}
 
+		// No need to suggest alternatives if the current query already returned results.
+		if ( $query->found_posts > 0 ) {
+			return false;
+		}
+
 		$term = $this->get_suggested_term( $query );
 		if ( empty( $term ) ) {
 			return false;
 		}
 
+		// No need to suggest the same term the user already typed.
+		$search_term = $query->query_vars['s'] ?? '';
+		if ( strtolower( $term ) === strtolower( $search_term ) ) {
+			return false;
+		}
+
 		$html = sprintf( '<span class="ep-spell-suggestion">%s: <a href="%s">%s</a>?</span>', esc_html__( 'Did you mean', 'elasticpress' ), get_search_link( $term ), $term );
 
 		$html .= $this->get_alternatives_terms( $query );
@@ -296,6 +307,12 @@ public function automatically_redirect_user() {
 			return;
 		}
 
+		// Do not redirect to the same term the user already searched for.
+		$search_term = $wp_query->query_vars['s'] ?? '';
+		if ( strtolower( $term ) === strtolower( $search_term ) ) {
+			return;
+		}
+
 		$url = get_search_link( $term );
 		$url = add_query_arg(
 			[

tests/php/features/TestDidYouMean.php

@@ -116,6 +116,9 @@ public function testGetSearchSuggestionMethod() {
 
 		$this->assertTrue( $query->elasticsearch_success );
 
+		// Force no results so the suggestion is displayed.
+		$query->found_posts = 0;
+
 		$expected = sprintf( '<span class="ep-spell-suggestion">Did you mean: <a href="%s">test</a>?</span>', get_search_link( 'test' ) );
 		$this->assertEquals( $expected, ElasticPress\Features::factory()->get_registered_feature( 'did-you-mean' )->get_suggestion( $query ) );
 	}
@@ -143,6 +146,9 @@ public function testGetSearchSuggestionMethodReturnsSuggestionForMainQuery() {
 
 		$query = $query->query( $args );
 
+		// Force no results so the suggestion is displayed.
+		$wp_query->found_posts = 0;
+
 		$expected = sprintf( '<span class="ep-spell-suggestion">Did you mean: <a href="%s">test</a>?</span>', get_search_link( 'test' ) );
 		$this->assertEquals( $expected, ElasticPress\Features::factory()->get_registered_feature( 'did-you-mean' )->get_suggestion() );
 	}
@@ -180,6 +186,10 @@ function ( $html, $terms, $query ) use ( $expected_result ) {
 				's' => 'teet',
 			]
 		);
+
+		// Force no results so the suggestion is displayed.
+		$query->found_posts = 0;
+
 		$this->assertEquals( $expected_result, ElasticPress\Features::factory()->get_registered_feature( 'did-you-mean' )->get_suggestion( $query ) );
 	}
 
@@ -338,6 +348,9 @@ public function testEPSuggestionsAction() {
 		$wp_the_query = $query;
 		$wp_query     = $query;
 
+		// Force no results so the suggestion is displayed.
+		$query->found_posts = 0;
+
 		ob_start();
 		do_action( 'ep_suggestions' );
 		$output = ob_get_clean();
@@ -371,6 +384,9 @@ public function testEPSuggestionsActionOtherThanMainQuery() {
 
 		parse_str( 'ep_suggestion_original_term=Original Term', $_GET );
 
+		// Force no results so the suggestion is displayed.
+		$query->found_posts = 0;
+
 		ob_start();
 		do_action( 'ep_suggestions', $query );
 		$output = ob_get_clean();
@@ -457,4 +473,70 @@ public function test_get_settings_schema() {
 			$settings_keys
 		);
 	}
+
+	/**
+	 * Tests that get_suggestion returns false when the current search term already has results.
+	 */
+	public function testGetSuggestionNotShownWhenResultsExist() {
+		$this->ep_factory->post->create( [ 'post_content' => 'Shirt product' ] );
+		$this->ep_factory->post->create( [ 'post_content' => 'Shift product' ] );
+
+		ElasticPress\Elasticsearch::factory()->refresh_indices();
+
+		$query = new \WP_Query(
+			[
+				's' => 'shirt',
+			]
+		);
+
+		$this->assertTrue( $query->elasticsearch_success );
+		$this->assertGreaterThan( 0, $query->found_posts );
+		$this->assertFalse( ElasticPress\Features::factory()->get_registered_feature( 'did-you-mean' )->get_suggestion( $query ) );
+	}
+
+	/**
+	 * Tests that get_suggestion returns false when the top suggestion matches the original term.
+	 */
+	public function testGetSuggestionNotShownWhenTopSuggestionMatchesOriginalTerm() {
+		$query                        = new \WP_Query(
+			[
+				's' => 'shirt',
+			]
+		);
+		$query->found_posts           = 0;
+		$query->suggested_terms       = [
+			'options' => [
+				[
+					'text' => 'shirt',
+				],
+			],
+		];
+		$query->query_vars['s']       = 'shirt';
+		$query->elasticsearch_success = true;
+
+		$this->assertFalse( ElasticPress\Features::factory()->get_registered_feature( 'did-you-mean' )->get_suggestion( $query ) );
+	}
+
+	/**
+	 * Tests that get_suggestion returns false when the top suggestion matches the original term with different casing.
+	 */
+	public function testGetSuggestionNotShownWhenTopSuggestionMatchesOriginalTermCaseInsensitive() {
+		$query                        = new \WP_Query(
+			[
+				's' => 'shirt',
+			]
+		);
+		$query->found_posts           = 0;
+		$query->suggested_terms       = [
+			'options' => [
+				[
+					'text' => 'Shirt',
+				],
+			],
+		];
+		$query->query_vars['s']       = 'shirt';
+		$query->elasticsearch_success = true;
+
+		$this->assertFalse( ElasticPress\Features::factory()->get_registered_feature( 'did-you-mean' )->get_suggestion( $query ) );
+	}
 }